| /* s_logbl.c -- long double version of s_logb.c. |
| * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz. |
| */ |
| |
| /* |
| * ==================================================== |
| * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| * |
| * Developed at SunPro, a Sun Microsystems, Inc. business. |
| * Permission to use, copy, modify, and distribute this |
| * software is freely granted, provided that this notice |
| * is preserved. |
| * ==================================================== |
| */ |
| |
| #if defined(LIBM_SCCS) && !defined(lint) |
| static char rcsid[] = "$NetBSD: $"; |
| #endif |
| |
| /* |
| * long double logbl(x) |
| * IEEE 754 logb. Included to pass IEEE test suite. Not recommend. |
| * Use ilogb instead. |
| */ |
| |
| #include "math.h" |
| #include "math_private.h" |
| #include <math_ldbl_opt.h> |
| |
| #ifdef __STDC__ |
| long double __logbl(long double x) |
| #else |
| long double __logbl(x) |
| long double x; |
| #endif |
| { |
| int64_t lx,hx; |
| GET_LDOUBLE_WORDS64(hx,lx,x); |
| hx &= 0x7fffffffffffffffLL; /* high |x| */ |
| if((hx|(lx&0x7fffffffffffffffLL))==0) return -1.0/fabs(x); |
| if(hx>=0x7ff0000000000000LL) return x*x; |
| if((hx>>=52)==0) /* IEEE 754 logb */ |
| return -1022.0; |
| else |
| return (long double) (hx-0x3ff); |
| } |
| long_double_symbol (libm, __logbl, logbl); |
